Get system information with Windows Management Instrumentation (WMI) and SWbemLocator

Windows Management Instrumentation (WMI) is the Microsoft implementation of Web-Based Enterprise Management (WBEM), which is an industry initiative to develop a standard technology for accessing management information in an enterprise environment. WMI uses the Common Information Model (CIM) industry standard to represent systems, applications, networks, devices, and other managed components.

It uses objects such as SWbemLocator, SWbemObjectSet, SWbemObject, SWbemProperty to connect to available WMI services and retrieve data. I had to learn about these for a project I was working on so I thought to include some code in here which may save someone else some get-up-to-speed time. Here is an instructive module which uses WMI and the SWbemLocator object to retrieve raw performance data.

Place the following code in a module and set a Project reference to the "Microsoft WMI Scripting Library":

Code:

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Option Explicit

Private Declare Function GetCurrentProcessId Lib "kernel32.dll" () As Long

Sub Main()
    Dim lngCurrentProcessID As Long
    lngCurrentProcessID = GetCurrentProcessId

    Dim lngErrCode  As Long
    Call GetProcessRawPerformanceData(lngCurrentProcessID, lngErrCode)

End Sub

Private Sub GetProcessRawPerformanceData(ByVal plngProcessID As Long, ByRef plngErrCode As Long)
    On Error GoTo PROC_ERROR
   
    '// Purpose: Get Process Raw Performance data for given process
    '// using Windows Management Instrumentation (WMI)

   
    '//These declarations require a reference be set to Microsoft WMI Scripting Library (c:\windows\syswow64\wbemdisp.tlp)
    Dim objLocator      As WbemScripting.SWbemLocator  'Wbem = Web-Based Enterprise Management
    Dim objService      As WbemScripting.SWbemServices
    Dim objProcesses    As WbemScripting.SWbemObjectSet
    Dim objProcess      As WbemScripting.SWbemObject
    Dim objProp        As WbemScripting.SWbemProperty

''    '//This version of the declarations requires no reference to be set (but is slower than above)
''    Dim objLocator      As Object
''    Dim objService      As Object
''    Dim objProcesses    As Object
''    Dim objProcess      As Object
''    Dim objProp        As Object
   
    '--Retrieve a locator object
    Dim strObjectName  As String
    strObjectName = "WbemScripting.SWbemLocator"
   
    Set objLocator = CreateObject(strObjectName)
    If objLocator Is Nothing Then
        plngErrCode = vbObjectError
        GoTo PROC_EXIT
    End If
   
    '--Log on to the namespace
    'If you do not specify a computer in the call to ConnectServer,
    'then WMI connects to the local computer. If you do not specify a namespace,
    'then WMI connects to the namespace specified in the registry key.
    Dim strServer      As String
    Dim strNamespace    As String
   
    strServer = "."
    strNamespace = "root\cimv2"
   
    Set objService = objLocator.ConnectServer(strServer, strNamespace)
    If objService Is Nothing Then
        plngErrCode = vbObjectError
        GoTo PROC_EXIT
    End If
   
    '-- query for the desired data
    Dim strProcessID    As String
    Dim strQuery        As String
   
    strProcessID = CStr(plngProcessID)
    strQuery = "Select * from Win32_PerfRawData_PerfProc_Process Where IDProcess = " & strProcessID
   
    Set objProcesses = objService.ExecQuery(strQuery)
    If objProcesses Is Nothing Then
        plngErrCode = vbObjectError
        GoTo PROC_EXIT
    End If
   
    '-- validate results (should be only one process matching the given process ID)
    If objProcesses.Count <> 1 Then
        GoTo PROC_EXIT
    End If
   
    '-- get a reference to the process
    Set objProcess = objProcesses.ItemIndex(0)  '0-based collection
    If objProcess Is Nothing Then
        plngErrCode = vbObjectError
        GoTo PROC_EXIT
    End If
   
    '-- iterate through the process info, getting each Property Name and Value
    Const COLON_SPACE      As String = ": "
   
    Dim strPropName        As String
    Dim strPropValue        As String
    Dim strPropNameAndValue As String

    With objProcess
        For Each objProp In .Properties_
            With objProp
                '...property name
                strPropName = .Name
               
                '...property value
                If .CIMType = wbemCimtypeString Then
               
                    'handle Null value case
                    If IsNull(.Value) Then
                        strPropValue = .Value & ""
                    Else
                        strPropValue = .Value
                    End If
                Else
                    strPropValue = CStr(.Value)
                End If
               
            End With
            strPropNameAndValue = strPropName & COLON_SPACE & strPropValue
           
            Debug.Print strPropNameAndValue
        Next
    End With
       
PROC_EXIT:
    If Not (objProp Is Nothing) Then Set objProp = Nothing
    If Not (objProcess Is Nothing) Then Set objProcess = Nothing
    If Not (objProcesses Is Nothing) Then Set objProcesses = Nothing
    If Not (objService Is Nothing) Then Set objService = Nothing
    If Not (objLocator Is Nothing) Then Set objLocator = Nothing
   
    Exit Sub
   
PROC_ERROR:
    plngErrCode = Err.Number
   
    Resume PROC_EXIT
    Resume
End Sub

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Which produces this output in the Immediate window:

Quote:

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Caption:
CreatingProcessID: 18148
Description:
ElapsedTime: 131716427650480103
Frequency_Object: 10000000
Frequency_PerfTime: 2539025
Frequency_Sys100NS: 10000000
HandleCount: 584
IDProcess: 22304
IODataBytesPersec: 209762
IODataOperationsPersec: 384
IOOtherBytesPersec: 48018
IOOtherOperationsPersec: 3018
IOReadBytesPersec: 200751
IOReadOperationsPersec: 372
IOWriteBytesPersec: 9011
IOWriteOperationsPersec: 12
Name: VB6
PageFaultsPersec: 44630
PageFileBytes: 84942848
PageFileBytesPeak: 146866176
PercentPrivilegedTime: 206250000
PercentProcessorTime: 249218750
PercentUserTime: 42968750
PoolNonpagedBytes: 56880
PoolPagedBytes: 647552
PriorityBase: 8
PrivateBytes: 84942848
ThreadCount: 14
Timestamp_Object: 131716434306142289
Timestamp_PerfTime: 198274349621
Timestamp_Sys100NS: 131716434306142289
VirtualBytes: 480518144
VirtualBytesPeak: 499048448
WorkingSet: 122535936
WorkingSetPeak: 143794176
WorkingSetPrivate: 72695808

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